#include<stdio.h>
int main()
{
    int n , x , y , a , b , c;
    scanf("%d%d%d",&n,&x,&y);
    c = y%x;
    if(c==0){a=y/x; b=n-a; printf("%d",b);}
    else{a=y/x+1;b=n-a;printf("%d",b);}
    return 0;
}
